ath6kl: cleanup ath6kl_priv()

It really should not return a void pointer. Also remove useless casts
from its users.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>
diff --git a/drivers/net/wireless/ath/ath6kl/cfg80211.c b/drivers/net/wireless/ath/ath6kl/cfg80211.c
index a2dd0fc..a58bea4 100644
--- a/drivers/net/wireless/ath/ath6kl/cfg80211.c
+++ b/drivers/net/wireless/ath/ath6kl/cfg80211.c
@@ -704,7 +704,7 @@
 static int ath6kl_cfg80211_disconnect(struct wiphy *wiphy,
 				      struct net_device *dev, u16 reason_code)
 {
-	struct ath6kl *ar = (struct ath6kl *)ath6kl_priv(dev);
+	struct ath6kl *ar = ath6kl_priv(dev);
 	struct ath6kl_vif *vif = netdev_priv(dev);
 
 	ath6kl_dbg(ATH6KL_DBG_WLAN_CFG, "%s: reason=%u\n", __func__,
@@ -802,7 +802,7 @@
 static int ath6kl_cfg80211_scan(struct wiphy *wiphy, struct net_device *ndev,
 				struct cfg80211_scan_request *request)
 {
-	struct ath6kl *ar = (struct ath6kl *)ath6kl_priv(ndev);
+	struct ath6kl *ar = ath6kl_priv(ndev);
 	struct ath6kl_vif *vif = netdev_priv(ndev);
 	s8 n_channels = 0;
 	u16 *channels = NULL;
@@ -918,7 +918,7 @@
 				   const u8 *mac_addr,
 				   struct key_params *params)
 {
-	struct ath6kl *ar = (struct ath6kl *)ath6kl_priv(ndev);
+	struct ath6kl *ar = ath6kl_priv(ndev);
 	struct ath6kl_vif *vif = netdev_priv(ndev);
 	struct ath6kl_key *key = NULL;
 	u8 key_usage;
@@ -1044,7 +1044,7 @@
 				   u8 key_index, bool pairwise,
 				   const u8 *mac_addr)
 {
-	struct ath6kl *ar = (struct ath6kl *)ath6kl_priv(ndev);
+	struct ath6kl *ar = ath6kl_priv(ndev);
 	struct ath6kl_vif *vif = netdev_priv(ndev);
 
 	ath6kl_dbg(ATH6KL_DBG_WLAN_CFG, "%s: index %d\n", __func__, key_index);
@@ -1110,7 +1110,7 @@
 					   u8 key_index, bool unicast,
 					   bool multicast)
 {
-	struct ath6kl *ar = (struct ath6kl *)ath6kl_priv(ndev);
+	struct ath6kl *ar = ath6kl_priv(ndev);
 	struct ath6kl_vif *vif = netdev_priv(ndev);
 	struct ath6kl_key *key = NULL;
 	u8 key_usage;